Cookies with a moisture content above about 6% by weight are usually soft and cohesive. To produce cookies which retain enough moisture to be classified as soft, numerous humectants have been used. Exemplary thereof are raisins, raisin pastes, high fructose corn syrup, corn syrup, glycerine, and mixtures thereof. Without the use of such humectants, cookie doughs which contain sufficient water to compensate for volatilization during baking: 1) do not exhibit sufficient cohesiveness for forming into pieces on conventional commercial scale cookie forming equipment, 2) exhibit raw flavor or color qualities, and 3) most importantly, lose their soft texture within a week or within a few days even when properly packaged in air-tight packaging. Generally, increasing the humectant content of the cookie dough extends the textural stability of soft cookies.
Liquid humectants such as high fructose corn syrup, corn syrup, glycerin and molasses are readily dispersed through a dough for providing a homogeneously soft texture to the cookies. However, it has been found that I5 soft cookies which contain chocolate chips tend to exhibit "bloom" on the flavor chips under storage conditions. Bloom appears as a whitish deposit, either in the form of discrete particles or a continuous layer, which covers at least part of the surface of the flavor chip. Bloom may be caused by the formation of fat and/or sugar crystals on the surface of the chips. While bloom may occur on flavor chips other than chocolate chips, it is particularly apparent in dark chips. The whitish deposits are even more apparent in dark cookies, such as chocolate fudge cookies. Although bloom does not pose any health risk, it is aesthetically unappealing and may lead consumers to the conclusion that the whitish deposits are due to mold growth or rancidity, or that the product lacks freshness or richness.
It is believed that migration of water in soft cookies from the crumb portion to the flavor chip surface dissolves sugar in the chip. Recrystallization of the sugar, caused by a drop in temperature, results in the formation of sugar crystals which are visible as "sugar bloom". Sugar crystals or other non-fat solids on the flavor chip surface may also serve as nucleation sites for recrystallization of fat crystals. The fat which recrystallizes may have originated in the flavor chip or the shortening or fat used in forming the dough. It is believed that the fat components having a higher melting point serve as nucleation sites for the other fat components because upon cooling, the higher components reach their solidification temperature first. Additionally, the higher melting point components, particular those which solidify at temperatures above normally encountered cookie storage temperatures, have less time to crystallize. The more rapid crystallization results in an unstable crystal form which cannot transform into a stable form.
In producing soft cookies, the use of a shortening or fat which is completely liquid at normal cookie storage temperatures of less than about 100.degree. F., may result in excessive oven spread and/or oil seepage to the surface of the cookie. Undesireable puddles of liquid fat or greasiness tends to smear packaging material, develop rancidity, and causes annoyance upon handling of the product.
The present invention provides shelf-stable cookies having a moist, cake-like soft textured crumb structure over an extended period of time which exhibit resistance to fat and sugar bloom on flavor chips. Even though a shortening or fat which contains low proportions of solid fats at cookie storage temperatures is used to prevent bloom, the cookies do not exhibit excessive oven spread or seepage of liquid oil at those temperatures.